MR. FBANCIS JAMES SELBY, C. B. E., one of the small band of workers who formed the staff of the National Physical Laboratory in its early days and helped to develop it from small beginnings to an institution of world-wide renown, died on March 5. He joined the staff in 1903 to take charge of the prediction of tides which the Laboratory was about to carry out for the Indian Government, and to establish a Division for Optics to supplement the work of the Observatory Department at Kew. Selby was also secretary to the Director, an office which, if the range of his activities were considered, would have been better described as secretary of the Laboratory. In this position, which he made one of great importance in the Laboratory organization, he took a large share of administrative responsibility. His sympathy with the policy of Sir Richard Glazebrook particularly fitted him for this work, and those who knew the Laboratory well realized that it was no less fortunate in its secretary than in its first director. Everyone trusted him and valued his judgment and advice.